A vacuum insulation glass panel is used as a window or an outer wall to improve the efficiency of heating and cooling of a building, a house or the like. The vacuum insulation glass panel includes two glass panels which are spaced apart from each other in parallel. The edges of the glass panels are sealed by a seal to keep the space between the two glass panels at a reduced pressure lower than the atmospheric pressure. The space between the glass panels is maintained by a plurality of spacers.
An opening or an exhaust hole is formed in any one of the glass panels to form a vacuum space between the glass panels by pumping out or exhausting an air. A glass tube is connected to the opening, and a vacuum device is connected to the glass tube. After evacuating the space by the operation of the vacuum device, the glass tube is sealed by melting to maintain the space in vacuum. However, the glass tube protrudes from the surface of the glass panel and may be damaged.
Korean Patent Application Publication No. 10-2013-0076783 discloses a vacuum insulation glass panel manufacturing method and a glass panel manufactured by the method. In the method of this patent document, a glass solder is applied around an opening formed in any one of two glass panels, and a glass or metal closing-off cap is arranged on the glass solder. The two glass panels are put into a vacuum oven, and an air is exhausted from the space between the glass plates through the opening. When the glass solder reaches a softening temperature, the closing-off cap is pressed by a plunger to seal the opening.
The vacuum insulation glass panel manufacturing method described above has various problems. First, since the closing-off cap is arranged and held above the opening by a member such as a spring or the like, the closing-off cap may be displaced or dropped during the movement of the glass panels. Thus, there is a possibility that the opening may not be accurately closed by the closing-off cap. Secondly, after the opening is closed by the closing-off cap, the member may remain inside the glass panels, thereby causing noise and breakage. Thirdly, since the position of the opening formed in the glass panels is changed depending on the size of the vacuum insulation glass panel, the setting of the plunger for pressing the closing-off cap is considerably complicated.